The present invention relates to automatic fastening devices and, in particular, a fastening device that drives a fastener into a workpiece by effecting multiple blows upon the fastener. More specifically, the invention relates to a fastening device having a feed assembly operatively connected to a nose assembly for mechanically advancing the fastener into a fastener drive channel. Furthermore, the invention relates to a fastening device wherein a fastener drive channel has a guide surface adjacent the aperture of the nose assembly to direct the fastener as it is driven into the workpiece. The invention also relates to a fastening device having a releasable fastener assembly for releasably securing the nose assembly to the housing of the fastening device. The invention also relates to a fastening device having a control assembly for controlling the operation of the fastening device to conserve energy. Finally, the present invention relates to a coil of collated roofing nails wherein each of the nails is coated with a thermoplastic material that serves as a lubricant which facilitates driving of the nails. The coil of collated roofing nails is adapted for use with the fastening device.
The most typical type of nailing or fastening device used to drive a fastener into a workpiece is that of the xe2x80x9csingle strokexe2x80x9d type. In these types of devices, a driver assembly is driven to fasten a fastener into a workpiece with single blow or impact. A disadvantage of these devices is that they require very high levels of impact energy, especially when longer fastener lengths are used.
There have been some attempts to provide a xe2x80x9cmulti-strokexe2x80x9d fastening device, which employs a striker assembly, which is driven to provide a plurality of blows or impacts upon the fastener head for progressively fastening the fastener into a workpiece. Such devices have been proposed by U.S. Pat. Nos. 1,767,485; 2,796,608; 3,203,610; 4,183,453; 4,724,992; and 4,807,793. The disadvantage with these proposed devices is that the fastener striker assembly is driven through a plurality of driving strokes, the lengths of the strokes are progressively increased as the fastener is progressively driven into the workpiece. As a result, the timing for driving the striker assembly becomes more difficult to manage. In addition, because the stroke length of the striker assembly increases during the course of each fastening cycle, the xe2x80x9cfeelxe2x80x9d of the tool is somewhat irregular. Therefore, there is a need for a multi-stroke fastening device having a uniform stroke length.
Prior art fastening devices that drive a fastener into a workpiece with a single blow need not be concerned with the fastener driver maintaining a coupled relation with respect to the fastener being driven. Multi-blow fastening devices, on the other hand are presented with a unique problem in that if a plurality of fastening impacts are to be imparted upon a single fastener to drive the fastener into the workpiece, the tool tends to bounce off the fastener head with each drive stroke. This may lead to an inefficient and rather clumsy operation of the tool.
Typical multiple blow fastening devices are pneumatically operated, therefore there has been little concern to conserve power. A battery operated fastening device is a lot more mobile and requires less equipment and assembly to operate than pneumatically operated devices. Therefore, there is a need for a fastening device that is battery operated and is constructed and arranged to conserve power during a fastening operation.
Power fastening devices for driving nails into a workpiece come in a variety of types. The fasteners used in such fastening devices vary according to the application. Most fasteners are made from a steel material. It is known in the art that the diameter of the fastener shank has a bearing on the strength of the connection provided. Basically, the greater the shank diameter, the greater the securing function provided.
For certain applications, such as in, pneumatically operated framing nailers, it has been known that the framing nails can be coated with a thermoplastic material that partially liquifies while the nails are being driven and then acts as an adhesive when the thermoplastic again solidifies after the nails are driven into the workpiece.
The adhesive nature of the thermoplastic is advantageous for certain applications because it increases the strength of the connection without requiring enlargement of the metal shank diameter. An ancillary benefit to providing the thermoplastic coating is that it reduces the energy required to drive the nail into the workpiece.
A disadvantage of providing a thermoplastic coating onto fastening nails is that it significantly increases the cost of manufacture in comparison with the same nails that are not so coated.
Roofing nails, which typically have a shank diameter of about 0.120xe2x80x3xc2x10.0015xe2x80x3 and a head diameter of about 0.350xe2x80x3-0.438xe2x80x3, are typically used to fastener shingles onto a roof. Heretofore, roofing nails have not been coated because the shank and head dimensions are sufficiently large to provide a relatively strong connection, particularly in light of the typically relatively soft shingle material that often tears before the nails would be pulled out. The cost of coating roofing nails has been considered to far outweigh any benefit to be gained.
Through experimentation with the unique fastening device described herein, applicants have recognized that in the particular application of a battery operated roofing fastener assembly, conservation of energy (i.e., battery life) is critical. Therefore, although roofing nails provide a more than adequate securement of shingles without the need for coating the same, and although thermoplastic coating significantly adds to the cost of manufacture, applicants have determined that the amount of increase in battery life results from providing coated roofing nails warrants the added cost for this particular application.
In order to remove jams and repair fastening devices, it is necessary to remove the nose assembly of the fastener assembly. Typically, the nose assembly is fastened to the housing and requires tools to disassemble, thus increasing downtime. Therefore, there is a need for a fastening device which facilitates quick and easy removal of the nose assembly to remove jams, thus reducing downtime.
Because the fasteners of fastening devices are typically collated by a flexible collation material, the leading fastener tends to pivot about the collation material, as the fastener is driven into the workpiece, until the collation fractures. Substantial movement can disorient the fastener in the drive track. This may cause the fastener to be deformed and/or driven into the workpiece incorrectly. Therefore, there is a need to adjust the orientation of the fastener while the fastener is being driven into the workpiece.
It is an object of the present invention to provide a multi-stroke fastening device for driving fasteners into a workpiece. This multi-stroke fastening device provides a housing, a fastener drive track carried by the housing, a striker assembly guide track mounted within the housing, a striker assembly mounted in slidable relation within said guide track, a power drive assembly, and a feed mechanism. The striker assembly includes a driver member constructed and arranged to strike a fastener disposed in the fastener drive track. The striker assembly is constructed and arranged to be moved along the guide track through a plurality of alternating drive strokes and return strokes to effect a plurality of impacts of the driver member upon the fastener in order to drive the fastener into the workpiece. The striker assembly has a substantially constant drive stroke length relative to the guide track. The power drive assembly is constructed and arranged to drive the striker assembly to effect the plurality of impacts of the driver member upon the fastener, and the feed mechanism is constructed and arranged to feed successive fasteners into the drive track to be struck by the striker assembly.
It is also an object of the invention to provide a multi-stroke fastening device which includes a striker assembly having a drive stroke length which does not progressively increase as the fastener is progressively driven into the workpiece.
It is a further object of the present invention to provide a multi-stroke fastening device for driving fasteners into a workpiece, comprising a housing, a striker assembly guide track mounted within the housing, and a striker assembly mounted in slidable relation with respect to the guide track. The striker assembly includes a driver member constructed and arranged to strike a fastener to be driven into a workpiece. The striker assembly is moveable along the guide track through a plurality of alternating drive strokes and return strokes to effect a plurality of impacts of the driver member upon the fastener. Each drive stroke has substantially the same length. A power drive assembly is constructed and arranged to drive the striker assembly through the plurality of alternating drive strokes and return strokes to effect the plurality of impacts of the driver member upon the fastener. A nose assembly is carried by the housing and defines a fastener drive track along which the driver travels during the drive strokes and return strokes. Furthermore, a fastener head engaging structure is constructed and arranged to engage a portion of the head of the fastener to be driven at least during the return stroke. A resilient structure is operatively coupled to the fastener head engaging structure. The resilient structure is constructed and arranged to permit limited longitudinal movement of the fastener head engaging structure relative to the striker assembly guide track, and dampens impact of engagement between the fastener head engaging structure and the head of the fastener to be driven.
It is a further object of one embodiment of the present invention to provide a multi-stroke fastening device that employs a fastener impacting driver assembly that is coupled to the driving structure so that impacts of the driver assembly are very effectively damped to reduce vibrations and shock in the system. In accordance with this object, the present invention provides a multi-stroke fastening device for driving fasteners into a workpiece, comprising a housing. The nose assembly is carried by the housing and defines a drive track. A mechanical fastener feed mechanism includes a fastener feed pawl that moves successive fasteners into the drive track. A cylinder guide track is mounted within the housing, the cylinder guide track having a forward end and a rearward end. A driver assembly is disposed in slidably sealed relation with the cylinder guide track, the driver assembly being movable forwardly through the cylinder drive track during a fastener impacting drive stroke thereof and movable rearwardly through the cylinder guide track during a return stroke thereof. The driver assembly includes a driver member movable through the drive track during alternating drive strokes and return strokes to impart a plurality of impacts upon a fastener to be driven into the workpiece so as to drive the fastener into the workpiece. A piston is disposed in slidably sealed relation with the cylinder guide track, the piston being rearwardly spaced from the driver assembly, with an air space disposed between the piston and driver assembly. A motor is operatively connected with the piston and constructed and arranged to drive the piston forwardly and rearwardly through the cylinder guide track to effect the alternating drive strokes and return strokes. Movement of the piston forwardly through the cylinder guide track compresses air within the air space so as to force the driver assembly forwardly through the cylinder guide track to effect the fastener impacting drive stroke so that the driver member impacts the fastener to be driven.
It is a further object of the present invention to provide a fastening device that employs a manually operated feed assembly so that energy may be conserved. In accordance with this object, the present invention provides a fastening device for driving a fastener into a workpiece comprising a housing and a striker assembly movably mounted within the housing. The striker assembly includes a driver assembly adapted to strike the fastener to be driven into the workpiece. A nose assembly is operatively connected to the housing. The nose assembly has a fastener drive channel along which the driver assembly and the fastener travel when the fastener is driven into the workpiece. A mechanical feed assembly is operatively connected to the nose assembly for advancing a fastener into the fastener drive channel at a predetermined time. The feed assembly advances the fastener into the fastener drive channel in response to an application of a mechanical force on the nose assembly.
The present invention is directed to a fastening device for driving a fastener into a workpiece having a housing, and a striker assembly movably mounted within the housing. The fastening device also includes a magazine constructed and arranged to carry a coil of collated fasteners. In accordance with the present invention, the nose assembly includes a feed assembly constructed and arranged to advance a lead fastener within the coil of collated fasteners in response to manually generated movement of the nose assembly into the housing during a fastener driving operation. The nose assembly also includes a spring that biases the nose assembly outwardly from the housing. The spring is compressed in response to the manually generated movement of the nose assembly into the housing.
It is a further object of the present invention to provide a fastening device having an energy control assembly to control the operation of the device so that energy may be conserved. In accordance with this object, the present invention provides a fastening device for driving a fastener into a workpiece comprising a housing and a striker assembly movably mounted within the housing. The device includes an energy control assembly for controlling the operation of the fastening device. The energy control assembly controls the operation of the fastener device in order to conserve power and extend battery life.
The energy control assembly may include an actuator that terminates operation of the fastening device when actuated. The actuator is actuated in response to the nose assembly being moved a selected distance inwardly with respect to the housing. The energy control assembly further includes an adjuster assembly constructed and arranged to adjust the position of the actuator and hence adjust the selected distance which the nose assembly must move in order to actuate the actuator and thereby terminate operation of the fastening device.
It is a further object of the present invention to provide a fastening device having a nose releasing assembly to facilitate the removal of the nose assembly. In accordance with this object, the present invention provides a fastening device for driving at least one fastener into a workpiece comprising a housing and a striker assembly movably mounted within the housing. A nose assembly is releasably secured to the housing and has a fastener drive track along which the driver assembly and the at least one fastener travel when the at least one fastener is driven into the workpiece. The device includes a nose releasing assembly for releasably securing the nose assembly to the housing. The releasable fastener assembly permits easy removal of the nose assembly from the fastening device in the event of a fastener jam.
The present invention is also directed to fastening device for driving a fastener into a workpiece having a housing, a striker assembly movably mounted within the housing, a nose assembly releasably secured to the housing, and a manually operable nose releasing assembly constructed and arranged to releasably secure the nose assembly to the housing. The releasing assembly including a manually engageable release member being manually movable from a latched position to a released position.
It is a further object of the present invention to provide a fastening device that includes at least one guide surface for adjusting the orientation of the fastener while the fastener is being driven into the workplace. In accordance with this object, the present invention provides a fastening device for driving a fastener into a workpiece comprising a housing and a striker assembly movably mounted within the housing. A nose assembly is releasably secured to the housing and has a fastener drive channel along which the driver assembly and the fastener travel when the fastener is driven into the workpiece. The fastener drive channel terminates at an aperture in one end of the nose assembly through which the fastener passes as the fastener is driven into the workpiece. The fastener drive channel includes at least one guide surface adjacent the aperture to control the movement of the fastener within the guide channel.
The present invention is also directed to a multi-stroke fastening device for driving a fastener within a coil of collated fasteners into a workpiece. The fastening device comprising a housing, a striker assembly movably mounted within the housing, and nose assembly operatively connected to the housing. The nose assembly has a fastener drive channel along which the driver assembly and the fastener travel when the fastener is driven into the workpiece. The fastening device also includes a magazine assembly constructed and arranged to engage at least one fastener within the coil of fasteners in order to move a lead fastener within the coil of fasteners in a first direction toward the fastener drive channel. The lead fastener has a forward pointed end thereof tending to be moved in a second direction opposite the first direction in response to a rearward head end thereof being impacted by the driver assembly due to the interconnection of the collation material between the lead fastener and a subsequent fastener. In accordance with the present invention, the nose assembly includes an angled guide surface constructed and arranged to engage the tip of the lead fastener as it is being driven. The guide surface is angled so as to direct the tip of the lead fastener toward the first direction as the lead fastener is being driven.
In accordance with an embodiment of the present invention, the nose assembly further comprises a pivoted guide structure defining a pivoted guide surface disposed in opposing relation to the angled surface. The pivoted guide structure is biased towards a first position such that pivoted structure is disposed adjacent to the angled guide surface so that the pivoted guide surface and the angled guide surface form a fastener outlet which is dimensioned to be smaller than a head of the fastener. In operation, the head of a fastener engages the pivoted guide surface as the fastener is being driven so as to force the pivoted guide structure away from the angled guide surface against the spring bias to enable the outlet to be sufficiently sized to permit the fastener head to pass therethrough. The angled guide surface and the pivoted guide surface guidably engaging the head as the head passes thereby.
It is a further object of the present invention to provide coated nails to facilitate driving of the nails into the workpiece so that energy may be conserved. In accordance with this object, the present invention provides a coil of collated roofing nails comprising a plurality of collated roofing nails interconnected by a collation material. Each of the nails has a shank portion with a shank diameter of about 0.120xe2x80x3xc2x10.0015xe2x80x3 and a head portion with a head diameter of about 0.350xe2x80x3 to 0.438xe2x80x3. Each of the nails is coated with a thermoplastic material that serves as a lubricant which facilitates driving of the nails into a workpiece so as to reduce the energy required to drive the nails into the workpiece.
These and other objects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, the principles of this invention.